Develop Reference

SharedPreferences as Singleton class. What is right way?

I developing an app which may often use ability to store/get some pair/value data in any app place such as an activity or it fragments. I decided use for it singleton. Is my class coded in right way?
public class StorageManager {
private static StorageManager instance;
public static final String PREF_NAME = "app_settings";
private SharedPreferences preferences;
private SharedPreferences.Editor editor;
public static StorageManager getInstance(Context context) {
if(instance == null)
instance = new StorageManager(context.getApplicationContext());
return instance;
}
private StorageManager(Context context) {
preferences = context.getSharedPreferences(PREF_NAME, Context.MODE_PRIVATE);
editor = preferences.edit();
}
public void setUserEmail(String token)
{
editor.putString("email", token);
editor.commit();
}
public String getUserEmail()
{
return preferences.getString("email", "");
}
}

Another clean way to achieve the same :)
public enum AppSharedPref {
instance;
SharedPreferences sharedPreferences;
// setter of the property.
public void setWeatherUpadte(int value) {
sharedPreferences = PreferenceManager.getDefaultSharedPreferences(AppLevelConstraints.getAppContext());
sharedPreferences.edit().putInt("Weather", value).apply();
}
// getter of the property.
public int getWeatherUpadte() {
sharedPreferences = PreferenceManager.getDefaultSharedPreferences(AppLevelConstraints.getAppContext());
return sharedPreferences.getInt("Weather", 0);
}
}
Simply access the property with :
AppSharedPref.instance.getWeatherUpadte();

Simple and Easy way to use SharedPrefrences
public class User {
SharedPreferences sharedPreferences;
public String getEnroll() {
enroll=sharedPreferences.getString("userdata","");
return enroll;
}
public void setEnroll(String enroll) {
this.enroll = enroll;
sharedPreferences.edit().putString("userdata",enroll).commit();
}
public void remove(){
sharedPreferences.edit().clear().commit();
}
String enroll;
Context context;
public User(Context context){
this.context=context;
sharedPreferences=context.getSharedPreferences("userinfo",Context.MODE_PRIVATE);
}
}
Create a user class and call it whenever you want to save the user login session
edt_enroll_login=(EditText)findViewById(R.id.edt_roll_login);
user_roll = edt_enroll_login.getText().toString().trim();
User user=new User(LOGIN.this);//pass the context to user class
user.setEnroll(user_roll);//save user session(here by enrollment number) in userinfo.xml file
Here i used login.java file to call user class
Just create User class object to check and remove userdata(session) -User user=new User(yourcallingactivity.this);
And to check if user is already login use user.getEnroll() method of user class,if user is already login then jump to home activity for user
For removing the session of user after logout use user.remove() method of user class.

Shared Preferences not working

I have a problem where my shared preferences are not working in a class file.I am confused and not able to solve it.Below is my file globalfile which saves data as follows.
public class globalfile extends Activity {
SharedPreferences sharedpreferences;
public static final String mypreference = "mypref";
public static final String Pwd = "pwdKey";
public static final String Email = "emailKey";
private static String global_username = "null/", global_pwd = "null/";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
sharedpreferences = getSharedPreferences(mypreference,
Context.MODE_PRIVATE);
}
public String getusername() {
global_username = sharedpreferences.getString(Email, "");
return global_username;
}
public String getuserpwd() {
global_pwd = sharedpreferences.getString(Pwd, "");
return global_pwd;
}
public void setusername(String someVariable) {
global_username = someVariable;
SharedPreferences.Editor editor = sharedpreferences.edit();
editor.putString(Email,global_username);
editor.commit();
}
public void setuserpwd(String someVariable) {
global_pwd = someVariable;
SharedPreferences.Editor editor = sharedpreferences.edit();
editor.putString(Pwd,global_pwd);
editor.commit();
}
}
I first called setuserpwd() & setusername() then getuserpwd() & getusername() from another activity using object of class globalfile.But always returns null.although if I use this code without shared pref.it is working fine

create an instance of Activity with Activity class object
Technically, you can create an instance of an Activity class. but, activity instance would be useless because its underlying Context would not have been set up.
The rule is that you should never ever create instances of Android components (Activity, Service, BroadcastReceiver, Provider) yourself (using the new keyword or other means). These classes should only ever be created by the Android framework, because Android sets up the underlying Context for these objects and also manages the lifecycle.
I think your newly created activity object can't get actual context. so try to avoid your current flow. I suggest you to create a separate class that may use as factory class and I think your problem will solved.
Or another solution would be like this :
Context context = /*get application context*/
SharedPreferences sharedPref = context.getSharedPreferences(
getString(R.string.preference_file_key), Context.MODE_PRIVATE);
/*get value from this sharedPref*/
So you don't need to create activity class object and here you should avoid your previous getter method to get value.

change you globalfile to be a utility class and not an activity so it can be used really easily by other parts of your app (that aren't an activity but have access to an android context).
public class Global {
private final SharedPreferences sharedpreferences;
public static final String mypreference = "mypref";
public static final String Pwd = "pwdKey";
public static final String Email = "emailKey";
private static String global_username = "null/",
global_pwd = "null/";
public Global(Context context) {
this.sharedpreferences = context.getSharedPreferences(mypreference,
Context.MODE_PRIVATE);
}
public String getusername() {
global_username = sharedpreferences.getString(Email, "null/");
return global_username;
}
public String getuserpwd() {
global_pwd = sharedpreferences.getString(Pwd, "null/");
return global_pwd;
}
public void setusername(String someVariable) {
global_username = someVariable;
sharedpreferences.edit().putString(Email,global_username).commit();
}
public void setuserpwd(String someVariable) {
global_pwd = someVariable;
sharedpreferences.edit().putString(Pwd,global_pwd).commit();
}
}
And here's how to use your new util class
Global global = new Global(context);
global.setusername("foo");
Log.d("TAG", "username from prefs = " + global.getusername());
global.setuserpwd("bar");
Log.d("TAG", "password from prefs = " + global.getusername());

How to get values from shared preferences for class by another class

I want to get a string from my shared preference file and use for more classes, but I don't know why not work.
My reader class is:
import android.app.Activity;
import android.content.SharedPreferences;
public class A {
public static String url2;
public void execute() {
String URLPref = "URL";
SharedPreferences prefs = getSharedPreferences("com.exam.search_preferences",Activity.MODE_PRIVATE);
url2 = prefs.getString(URLPref , "");
}
private SharedPreferences getSharedPreferences(String string,
int modePrivate) {
return null;
}
}
And the second class that uses the string
public class SearchHome extends Activity {
static String url2;
A cls2= new A();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.search_activity);
cls2.execute();
url2 = A.url2;
Toast.makeText(getApplicationContext(),"URL:" + url2 ,
Toast.LENGTH_LONG).show();
...
Sorry for my bad english, I never learned.But I'm trying!

You need to pass the Context to your class A, because you can get the SharedPreferences from a Context object. NOTE, an Activity is a Context to some extend
public class A {
public static String url2;
/** #param context used to get the SharedPreferences */
public void execute(Context context) {
String URLPref = "URL";
SharedPreferences prefs = context.getSharedPreferences("com.exam.search_preferences",Activity.MODE_PRIVATE);
url2 = prefs.getString(URLPref , "");
}
}
And then pass the Context to your execute method
public class SearchHome extends Activity {
static String url2;
A cls2= new A();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.search_activity);
// pass context 'this' to the execute function
// This works, because SearchHome extends Activity
cls2.execute(this);
url2 = A.url2;
...

if your data is not confidential it would be a lot easier if you can make a class specially for shared preference and have other activities access it. you will save a lot of time and code will be a lot simpler to follow up
public class HelperShared {
public static final String score = "Score";
public static final String tag_User_Machine = "tag_User_Machine",
tag_Machine_Machine = "tag_Machine_Machine",
tag_Draw_Machine = "tag_Draw_Machine",
tag_Total_Machine = "tag_Total_Machine";
public static SharedPreferences preferences;
public static Editor editor;
public HelperShared(Context context) {
this.preferences = context.getSharedPreferences(score,
Activity.MODE_PRIVATE);
this.editor = preferences.edit();
}
/*
* Getter and Setter methods for Machine
*/
public void setUserMachine(int UserMachine) {
editor.putInt(tag_User_Machine, UserMachine);
editor.commit();
}
public void setMachineMachine(int MachineMachine) {
editor.putInt(tag_Machine_Machine, MachineMachine);
editor.commit();
}
public void setDrawMachine(int DrawMachine) {
editor.putInt(tag_Draw_Machine, DrawMachine);
editor.commit();
}
public void setTotalMachine(int TotalMachine) {
editor.putInt(tag_Total_Machine, TotalMachine);
editor.commit();
}
public int getUserMachine() {
return preferences.getInt(tag_User_Machine, 0);
}
public int getMachineMachine() {
return preferences.getInt(tag_Machine_Machine, 0);
}
public int getDrawMachine() {
return preferences.getInt(tag_Draw_Machine, 0);
}
public int getTotalMachine() {
return preferences.getInt(tag_Total_Machine, 0);
}
}

private SharedPreferences getSharedPreferences(String string,
int modePrivate) {
return null;
}
problem is here.
return null;
you have to return valid SharedPreferences object. otherwise you will always get NullPointerException.

Call this when you want to put a pref:
putPref("myKey", "mystring", getApplicationContext());
Call this when you want to get a pref:
getPref("myKey", getApplicationContext());
You can use SharedPreferences to save any primitive data: booleans, floats, ints, longs, and strings. This data will persist across user sessions (even if your application is killed).
Different Modes:
1 MODE_APPEND
This will append the new preferences with the already exisiting preferences
2 MODE_ENABLE_WRITE_AHEAD_LOGGING
Database open flag. When it is set , it would enable write ahead logging by default
3 MODE_MULTI_PROCESS
This method will check for modification of preferences even if the sharedpreference instance has already been loaded
4 MODE_PRIVATE
By setting this mode , the file can only be accessed using calling application
5 MODE_WORLD_READABLE
This mode allow other application to read the preferences
6 MODE_WORLD_WRITEABLE
This mode allow other application to write the preferences
Read More

You just need to make shared prefrences object in class where you want to have data
SharedPreferences prefrences = getSharedPreferences("my prefs",MODE_PRIVATE)
Editor editor = prefrences.edit();
String s = edit.getString("your key",value);
hope it helps !

SharedPreferences cleared if remove the app from recent activity android

I'm using SharedPreferences in my project with MODE_PRIVATE, when i cleared the app from recent activity list, and opens the app again, all my preference data is cleared.
I'm using this class fro setting and getting preference.
public class Preferences {
private Context _context;
private SharedPreferences _preferences;
private Editor _editor;
private String prefName = "pref";
//=====
public Preferences(Context context){
_context = context;
_preferences = this._context.getSharedPreferences(prefName, Context.MODE_PRIVATE);
_editor = this._preferences.edit();
}
//=====
public Preferences commit(){
_editor.commit();
return this;
}
//=====
public Preferences set(String key, String value){
_editor.putString(key, value);
return this;
}
//=====
public String get(String key){
return _preferences.getString(key, "");
}
//=====
public Preferences set(String key, int value){
_editor.putInt(key, value);
return this;
}
//=====
public int getInt(String key){
return _preferences.getInt(key, 0);
}
//=====
public Preferences setBoolean(String key, boolean value){
_editor.putBoolean(key, value);
return this;
}
//=====
public void removeKey(String key){
_editor.remove(key);
}
//=====
public boolean getBoolean(String key){
return _preferences.getBoolean(key, false);
}
}
can any one help me ...??

change your set method like this
public Preferences set(String key, int value){
_editor.putInt(key, value);
_editor.commit();
return this;
}
you don't need separate commit() into independent method.
good luck

this is another example, in this example i create a value that save my city name and when my app lunched i check for existing , if exist the value of that key returned to me.
SharedPreferences sp;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// define sp
sp=getSharedPreferences("test", Context.MODE_PRIVATE);
// get sp value if exist
if(sp.contains("EkbatanApp")){
String spResult=sp.getString("EkbatanApp", "");
}
}
//save key
public void SaveSettingOnClick(View v){
Editor editor=sp.edit();
editor.putString("EkbatanApp", "Borujerd");
editor.commit();
}

Getting/Setting values SharedPreference globaly

Hi i have a class (MyCustomForm.xml) which i use as a LoginForm for the user.
Now i want to save and load the value from the username(EditText) from the LoginForm using SharedPreferences but i do not know how to set the value of username saved by SharedPreferences into the EditText in LoginForm(MyCustomForm.xml).
I was thinking to save the value in OnPause in my Main.xml and load the value through OnCreate in the class MyCustomForm.xml
Generaly i would like to use SharedPreferences globaly.
How would this look like?
Can somebody please help me to get on the right track?
It was thinking something like this Main.xml:
public class AndroidLogin extends Activity implements OnClickListener {
#Override
protected void onPause() {
super.onPause();
Editor e = mPrefs.edit();
e.putString(USERNM, username);
e.commit();
}
}
Code MyCustomForm (LoginForm):
public class MyCustomForm extends Dialog {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(com.sencide.R.layout.inlogdialog);
EditText userTest = (EditText)findViewById(R.id.txtUserName);
userTest.setText(USERNM);
}
}

You can do something like this :
SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(YouActivity.this);
String servername = settings.getString("sharedPreferencesKey", "defaultValue");
server.setText(servername); // EditText
And you store data like this :
SharedPreferences.Editor editor = settings.edit();
editor.putString("server", "serverName");
EDIT :
This piece of code should do the trick for you :
SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(context.getApplicationContext());
String servername = settings.getString("sharedPreferencesKey", "defaultValue");

You need to use the Prefs & Editor
SharedPreferences spOptions;
SharedPreferences.Editor spOptionEditor;
spOptions = getSharedPreferences("yourKey", 0);
spOptionEditor = spOptions.edit();
string username = spOptions.getString("USERNM", null)
null represents the default value if you don't have anything stored yet
You store the data like this:
spOptionEditor.putString("USERNM", txtUsername.getText().toString());
spOptionEditor.commit();

Generally I would recommend you to save the username on a valid login, and not in any lifecycle method.
Then change myForm to this:
public class MyCustomForm extends Dialog {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(com.sencide.R.layout.inlogdialog);
String s = getContext().getSharedPreferences("prefName", Mode.PRIVATE).getString(USERNM);
EditText userTest = (EditText)findViewById(R.id.txtUserName);
userTest.setText(s);
}
}

public void sharedPrefernces() {
sh_Pref = getSharedPreferences("Login Credentials", MODE_PRIVATE);
toEdit = sh_Pref.edit();
toEdit.putString("Username", username);
toEdit.putString("Password", password);
toEdit.commit();
}
Read more: http://mrbool.com/how-to-implement-shared-preferences-in-android/28370#ixzz34ymRp6mN

Just create a file called preferences... and store the value to it using different methods.
Use the methods people have suggested to put and get data from them...
public class Settings extends PreferenceActivity implements
OnSharedPreferenceChangeListener{
public static final String PREFS_PRIVATE = "PREFS_PRIVATE";
public static final String MASTERKEY = "!##$%^&*";
public static final String KEYA = "KEYA";
public static final String KEYB = "KEYB";
public static final String KEYC = "KEYC";
--- the create and get methods for getting and sharing data in the prefs... .....
public static void createPreference(Context context){
getPrefs(context).edit().putString(KEYA, "Default");
getPrefs(context).edit().putInt(KEYB, 0);
getPrefs(context).edit().putLong(KEYC, 0);
getPrefs(context).edit().putBoolean(KEYD, false);
getPrefs(context).edit().commit();
}
public static SharedPreferences getPrefs(Context context) {
return context.getSharedPreferences(PREFS_PRIVATE, 0);
}
public static String getUsername(Context context) {
getPrefs(context).getString(USERNAME, "default");
}
public static void setUsername(Context context, String value) {
getPrefs(context).edit().putString(USERNAME, value).commit();
}
}
..... so on and so forth..... Just implement it if you find any doubt or any thing that you need in more specific please let me know.